Prescription (Rx) drug abuse has emerged as a significant problem among young adults in America. While research indicates a dear pattern of abuse of Rx drugs by young adults, the social, psychological, and subcultural contexts associated with Rx drug abuse and related risk taking among young adults need further explication, particularly given that it may elevate HIV risk via sexual risk taking and injection drug use. Our goal is to conduct a study of the patterns and contexts of Rx drug abuse and risk taking among young adults in the New York City (NYC) metropolitan area. This grant application proposes a mixed-methods study of the abuse of various classes of Rx drugs, including pain killers, sedatives, and stimulants, by young adults in club subcultures and the youth in their networks to whom they are connected. The goals of the study include explorations of a) the contextual factors associated with Rx drug initiation and continued patterns of abuse among young adults, in particular transitions to illegal opiates or injection drug use, b) how gender and sexual orientation bear upon Rx drug abuse and risk among young adults, and c) the risks associated with Rx drug abuse, including sexual risk taking. A mixed-methods design, using ethnographic methods, qualitative interviews, and structured surveys, will be applied. We will use ethnographic methods including in-depth interviews to explore contextual factors related to Rx drug abuse and risk taking. The in-depth interviews utilize Critical Incident Measures to draw out narratives about initiation experiences and experiences with recent patterns of use. Beyond ethnographic methods, a structured survey will be used to obtain epidemiological data and data on factors related to Rx drug abuse and risk. We will recruit 400 Rx drug abusing young adults aged 18 to 29 in NYC using Respondent Driven Sampling (RDS). The survey will be administered a second time through an on-line survey provided to subjects at 12-months following the original assessment. The combination of these methods in this study will enable the development of a fuller contextual understanding of Rx drug abuse among young adults and its associated risks, including HIV risk, which will be instrumental in the development of health promotion activities and interventions.